Editing a document on a computer-based word processor is convenient. Mere keystrokes at a computer keyboard change the text of the document. The document can be changed as often as desired without using any paper. When a final version of the document is achieved, then the user prints out the document via a printer.
Even though a document may look acceptable when viewed during its creation with the computer, the reader may later detect errors upon reading a printed copy of the document. In addition, many documents are edited as printed documents, as a great number of people still have a preference for reading and editing documents on paper rather than reading the documents electronically through a display of the computer. In this case, after the desired changes are marked on the printed document, a user must take the edited printed document and return to the computer to make the desired changes in the electronic copy and reprint the document on paper. For people who like to first review and edit paper documents, this situation requires two editing steps: first making the edits and second implementing the edits via the computer. A third step of transporting the document is added when the printed document is at a location distant from the computer that generated the document or computer media storing the document. Finally, in many cases, an electronic copy of the printed document no longer exists or is otherwise unavailable.
For these reasons, more convenient ways of editing printed documents would desirable.